Obstetric and neonatal outcomes of maternal vitamin D supplementation: results of an open-label, randomized controlled trial of antenatal vitamin D supplementation in Pakistani women

Abstract

Objective: The objective of the study was to determine whether vitamin D (vitD) supplementation during pregnancy affects obstetric and neonatal outcomes.

Setting: The study was conducted at a university hospital in Karachi, Pakistan.

Methods: The study was a single-center, open-label, randomized, controlled trial of routine care (group A, 200 mg ferrous sulfate and 600 mg calcium daily) vs vitD supplementation (group B, 4000 IU vitamin D3 daily), started at 20 weeks and continued till delivery. Maternal serum samples of 25-hydroxyvitamin D (25OHD) were collected at baseline and delivery. Neonatal vitD status was assessed in cord blood or in neonatal serum samples within 48 hours of birth. Obstetric outcomes included gestational hypertension, gestational diabetes, and preterm labor, and neonatal well-being included small for gestational age, birth weight, length, head circumference, and 1- and 5-minute Apgar scores.

Results: Of 207 gravidae enrolled, 193 completed the trial. Maternal age, vitD status, and gestational age at enrollment were comparable between the two groups. At delivery, maternal 25OHD was increased in group B (18.3 ± 11 ng/dL vs 8.82 ± 11.84 ng/dL (P = .001) compared with group A (6.9 ± 7.0 ng/dL vs 6.32 ± 3.97 ng/dL, P = .06). The obstetric outcomes were comparable between the two groups (P > .05). Neonatal 25OHD levels were significantly higher in group B compared with group A (19.22 ± 12.19 ng/dL vs 6.27 ± 5.2 ng/dL). There was positive correlation between maternal and neonatal 25OHD levels (r = 0.83, P = .001). One- and 5-minute Apgar scores were significantly higher in group B (7.10 ± 0.66 vs 6.90 ± 0.50, P = .026, and 8.53 ± 0.68 vs 8.33 ± 0.81, P = .051, respectively). Neonatal anthropometric parameters were comparable between the two groups (P > .05).

Conclusion: Maternal vitD supplementation improved maternal and neonatal vitD status.

Trial registration: ClinicalTrials.gov NCT01418664.